In a field of photography, an optical lens is used to acquire visible light to capture the images. Moreover, the optical lens having a wide angle can acquire more visible light and is more widely used.
Generally, In order to get a more compact optical system, the size of image sensor has became smaller. If we keep the same resolution of sensors, the pixel size should be smaller to reduce the length of optical system, so the color aberration has became more and more important to optical design. Nowadays, an optical system with compact size, low optical aberration and good tolerance endurance are needed for the optical lens.